For quite some time, as you can see in the sidebar, I've interpreted the OD&D "round" as a short period of about 10 seconds in length (in accordance with pretty much anything developed after 1978).
But one thing I've had as a dilemma for quite some time is how to interpret the "turns" of OD&D, especially in regard to durations for spells and potions and the like (e.g., I left it undefined in the OED Book of Spells). I've gone back-and-forth in considering the AD&D-style 10-minute turn, or just saying a turn = round (10 seconds for me), etc. But what I've finally decided recently is to read occurrences of "turn" as 1 minute (for simplicity, say: 1 turn = 5 rounds). Truth is, it's even a throwback to the original game of Chainmail, for reasons which I'll outline below:
Advantages of the 1-minute turn:
(1) It's easy to interpret for players. When they look at the OD&D spell list and ask "what's a turn?" I can just say "1 minute" and no mental conversions are necessary.
(2) It matches what we might expect for the length of one scene. When I browse through the OD&D spell listings (usually 3, 6, or 12 turns duration) and think about the real-time length each spell "should" last, usually a few minutes (surely less than an hour) seems about right. God forbid I use the word "cinematic" here, but it is the case that an action beat in literature, television, movies, or music usually lasts on the order of a few minutes.
(3) It means we usually won't have to track spells in combat. Granted OD&D spells durations above (15, 30, or 60 rounds by the simple conversion), most of our combats will terminate before we reach these points. Admittedly there's a bit of a loss in not having the end-time of spells be a tactical consideration in combat, but it's definitely balanced by the ease of record-keeping.
(4) It's a return to the better-thought-out original rules in Chainmail. Recall that Chainmail starts its mass-combat rules with a "turn" of 1 minute (p. 8); and a smaller division of "rounds" for melee cycles (not well-defined, but you can see the distinction in the Fatigue rules, p. 11 -- thanks to UWSGuy for educating me on this). Interestingly, when Chainmail gets to the Man-to-Man rules, then it uniformly presents the action in terms of the "round" designator (see all of p. 25, etc.), even though later fantasy spells are in "turns" (p. 31-32). So this both makes sense as pacing and is compatible with what I'm doing here; "turns" of 1 minute, with man-to-man "rounds" of a smaller unit (like around 10 seconds, perhaps).
The fact that Gygax garbled the issue later when he got to OD&D Vol-3 by asserting that turns were 10 minutes, and rounds were 1 minute -- and then doubling down in defending the nonsense in the DMG -- shouldn't inhibit us from using an interpretation that is easy, sensible, and more true to the actual root of the game.